title: Designing oral vaccines targeting intestinal dendritic cells.
abstract: BACKGROUND
  Most pathogens colonize and invade the host at mucosal surfaces, such as the lung and the intestine. To combat intestinal pathogens the induction of local adaptive immune responses is required, which is mainly achieved through oral vaccination. However, most vaccines are ineffective when given orally owing to the hostile environment in the gastrointestinal tract. The encapsulation of antigens in biodegradable microparticulate delivery systems enhances their immunogenicity; however, the uptake of these delivery systems by intestinal immune cells is rather poor. Surface decoration of the particulates with targeting ligands could increase the uptake and mediate the selective targeting of the vaccine to intestinal antigen-presenting cells, including dendritic cells.
  
  
  METHODS
  In this review, current knowledge on dendritic cell subsets is discussed, along with progress in the development of selective antigen targeting to these cells, in addition to focusing on data obtained in mice and, where possible, the pig, as a non-rodent animal model for humans. Moreover, the potential use and benefits of Fcγ receptor-mediated targeting of antigen delivery systems are highlighted.
  
  
  CONCLUSIONS
  In conclusion, dendritic cell targeting ligands grafted on antigen carrier systems should preferably bind to a conserved endocytotic receptor, facilitating the design of a multispecies vaccine platform, which could elicit robust protective immune responses against enteric pathogens.
authors.affiliation: Laboratory of Immunology, Faculty of Veterinary Sciences, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Bert
authors.initials: B
authors.lastname: Devriendt
authors.forename: Bruno G
authors.initials: BG
authors.lastname: De Geest
authors.forename: Eric
authors.initials: E
authors.lastname: Cox
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003713:Dendritic Cells / Q000276:immunology*; D004337:Drug Carriers / Q000737:chemistry; D015195:Drug Design; D006801:Humans; D018928:Immunity, Mucosal; D007141:Immunoglobulin Fc Fragments / Q000276:immunology; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology*; D008024:Ligands; D011961:Receptors, Fc / Q000276:immunology; D057900:Transcytosis / Q000276:immunology; D014612:Vaccines / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D004337:Drug Carriers; D007141:Immunoglobulin Fc Fragments; D008024:Ligands; D011961:Receptors, Fc; D014612:Vaccines